Typical prior art hole cutters, also known as hole saws, comprise a circular base, a peripheral wall formed on one side of the base and extending axially therefrom, and a plurality of cutting teeth machined in the outer edge of the peripheral wall. The base, peripheral wall and cutting teeth are machined from a piece of steel to form a hole cutter of unitary construction. An example of a hole saw is illustrated in U.S. Pat. No. 5,803,678, which is incorporated by reference herein in its entirety.
Some hole saws are manufactured by forming the saw teeth in an elongated metal band, and then welding the metal band in a circular configuration onto a rigid cap plate. The cap defines a peripheral flange and recess for receiving the band, and the band is welded to the cap at the junction of the flange and band. The band theoretically should be round, and should define either a chamfered or radiused inner corner in order to allow the band to fully engage the surfaces of the peripheral flange and recess of the cap, and thereby allow the band to be securely welded to the cap. In some cases, the bands can become “out of round” or otherwise mis-shaped during handling, and/or the inner edge of the bands may include burrs or may not define a correct chamfer or radius. In these situations, the band will not seat itself properly on the cap.
Accordingly, it is an object of the present invention to provide an improved hole cutter that overcomes one or more of the above-described drawbacks and/or disadvantages.